Aircraft attitude indicator

ABSTRACT

An aircraft attitude indicator having a float for oscillation about a horizontal axis and for rotation about an axis normal to said axis. Indicating markings carried by the float and casing provide for fast observation of the attitude of the craft. An adjustable horizontal marker is provided for compensating for the trim of the craft.

United States Patent [72] Inventor Bruce W. Branick :3. l 1 w. 1,1380027th St.,PortArthur, Tex. 77640 [21]; Appl. No. 786,169 [22]-.Filed Dec.23,1968 [45] Patented Mar. 23, 1971 s41 'AIRCRAFI ATm'UbEINDICATOR T Claims, 6 Drawing Figs. 52 us. 01 33/206, 116/129,.33/215 51lnt.Cl G0lc9/20 1501-1, Fieldofsearch 33/206, 206.2, 2os.213,21s.2, 220;1 16/129, (Navigation) [56] ReferenoesCited UNITED STATES PA'IENTS1,359,711 11/1920 Kelnev s s 206021 FOREIGN PATENTS 544,493 1957 CanadaPn'mary Examiner-Leonard Forman Assistant Examiner-Dennis A. DearingAttorney-Everett G. Clements ABSTRACT: An aircraft attitude indicatorhaving a float for oscillation about a horizontal axis and for rotationabout an axis normal to said axis. Indicating markings carried by thefloat and casing provide for fast observation of the attitude of thecraft. An adjustable horizontal marker is provided for compensating forthe trim of the craft.

Pmimmmzsml 3'571 938 SHEET 2 or '2 INVENTOR BRUCE W. BRANICK aforesaidwith which contains no sion in manufacture.

tions in the trim of the craft.

It is a. further object of this invention to provide an attitudeindicator as aforesaid in which the bank and inclination of the l craftcan be accurately detennined by a glance at the instrument..:

a It is a further object of this inventionto produce a device as partsthat require high preci- It is a further object of this invention toaforesaid which is veryaccurate'. Theseand other objects of theinvention will become provide a device as manifest upon reading thefollowing description in conjunction with the accompanying drawingswherein: FIG. -1 is a perspectiveview of the indicator; I FIG. 2 is alongitudinal section takenthrough FIG. 1;

' FIG. 3 is a section taken on line 3-3 of FIG. 1;

FIG. 4 is a partial end view of FIG. 1;

FIG. Sis an end view of the float; and I FIG. 6 is a perspective view ofthe float mechanism. With reference to the drawings there is disclosed acasing in .the form of a cup-shaped housing 2. A mounting plate 4 issecured in fluidtight relation to the open end of the cup by bolts 6 anda gasket. 8, and is formedwith openings 10 for mounting on asupport. Aspherical outwardly curved window .12 has an annular flat mountingflange 13 which is secured to plate 4 in fluidtight relation by means ofany suitable bonding material and a gasket 14. I t I I A rigidhorizontal support leis mounted in the housing 2 and carries a bearingpedestal18 in which is secured an antifriction bearing 20 preferablyformed of a synthetic plastic such as Teflonf'A rod 22, having atone enda laterally extending leg 24 is pivotally mounted by the leg foroscillation, in

the bearing 20. The arc of oscillation is limited by stops 26, 28secured to the pedestal l8.

A float 30 is provided with a bearing 32 somewhat similar to the bearing20. and is mounted forfree rotary movement about the forward end of therod 22. A weight 34 ofsufficient mass to retain the float by its weightalmost completely submerged in the liquid in the casing as shown at 35.The weight 34 is moulded integral with the material of the float. Themass of the weight is thus also sufficient to rotate the float on therod as an axis to thereby maintain a radius and line 36 through theweight in a position normal to the horizon line 45 also inscribed on theface of the float. The bearing 32 is formed slightly larger thantheopening in the float and is made in sections that can be assembledaround the rod and then be forced into the opening to remain assembledand to hold captive an enlarged head 38 formed on the end of the rod.

- The float is preferably formed of a synthetic plastic that will not beaffected by the liquid in the casing. The liquid is preferably of amaterial that will not freeze under the temperatures encountered inflight. Styrofoam and'alcohol have been tried as the plastic and fluidand have worked well. However,

the float could obviously be made of other materials as for instance ametal shell; if desired. I

The float is formed with a spherical face 40 generated from the samecenter as the window 12 and has an accurate scale 42 and a verticalscale 44 inscribed thereon to indicate the angles of bank andinclination of the plane on which the instrument is marker 52 is formedwith a guide box 54 having an o ening therethrough congruent in shape tothe cross-sectiona shape of the track for guided movement along thetrack. Protuberance 53 is threaded to receive a threaded member 56having secured thereto a flexible shaft 58 formed with a recess 60 at 0the free end. Box 54 is provided with a circular opening to rotatablyreceive the flexible shaft and is provided with a set screw 62- havingan end fitted into recess 60. Rotation of threaded member 56 will causethe member to travel longitudinally in protuberance 53 and will drive Ithe horizontal marker along the track 50. The angle of bank is indicatedby using scale 42 and the track 50. as the reference. The angle ofinclination isv indicated by using scale 44 and the horizon marker asthe reference. The bank of the craft can be easily seen by noting theangle the surrogate forms with the horizon marker, and the horizonmarker can be adjusted by rotation of member 56.

- I claim: I I

. l. A flight attitude indicator for aircraft comprising a casing, afluid in said casing, an eccentrically weighted float, 'means pivotallymounting the float in the casing for swinging in a vertical plane abouta horizontal axis and for rotary movement about an axis normal thereto,saidtwo axes intersecting at a point horizontally displaced from thefloat, said float being buoyed by said fluid causing said swinging inresponse to a change in. attitude of said indicator; a sight window inthe case for viewing the float, indicating markings on the float forindicating the angle of the bank, and a fixed reference carried by thecasing for cooperationwith said markings to indicate the angle of bank.

2. An indicator as defined in claim 1 further including a surrogatemarking on the float anda horizon marker mounted over said sight windowexternally of the casing for cooperation I guide means for guiding themarker for travel on the track,

and means secured to the casing for driving the marker over the track.

5. An indicator as defined in claim 4 wherein the means for driving themarker comprises a manually adjustable screw and a flexible shaftsecured to said screw and rotatable in the marker.

6. An indicator as defined in claim 1 further including indicating.markings on the flat for indicating the inclination of the craft andmeans secured to the casing for cooperation with said further markingsto indicate the angle of inclination.

7. An indicator as defined in claim 1 wherein the means mounting thefloat for swinging comprises a bearing secured in the casing and a rodpivotally mounted by one end in said bearing. v

8. An indicator as defined in claim 7 wherein the means mounting thefloat for rotary movement comprises a bearing carried by the floatmounted on the other end of the rod.

9. An indicator as defined in claim 8 further including means secured tothe bearing secured in the casing for limiting the arc swinging of thefloat.

10. An indicator as defined in claim 9 further including baffles securedto said rod and float for damping the swinging and rotation of the floatin a liquid.

1. A flight attitude indicator for aircraft comprising a casing, a fluidin said casing, an eccentrically weighted float, means pivotallymounting the float in the casing for swinging in a vertical plane abouta horizontal axis and for rotary movement about an axis normal thereto,said two axes intersecting at a point horizontally displaced from thefloat, said float being buoyed by said fluid causing said swinging inresponse to a change in attitude of said indicator, a sight window inthe case for viewing the float, indicating markings on the float forindicating the angle of the bank, and a fixed reference carried by thecasing for cooperation with said markings to indicate the angle of bank.2. An indicator as defined in claim 1 further including a surrogatemarking on the float and a horizon marker mounted over said sight windowexternally of the casing for cooperation with the surrogate to indicatethe bank of the craft.
 3. An indicator as defined in claim 2 furtherincluding means for vertically adjusting the horizon marker.
 4. Anindicator as defined in claim 3 wherein the means for verticallyadjusting the marker comprises a track secured to and externally of thecasing and transversing the window, guide means for guiding the markerfor travel on the track, and means secured to the casing for driving themarker over the track.
 5. An indicator as defined in claim 4 wherein themeans for driving the marker comprises a manually adjustable screw and aflexible shaft secured to said screw and rotatable in the marker.
 6. Anindicator as defined in claim 1 further including indicating markings onthe flat for indicating the inclination of the craft and means securedto the casing for cooperation with said further markings to indicate theangle of inclination.
 7. An indicator as defined in claim 1 wherein themeans mounting the float for swinging comprises a bearing secured in thecasing and a rod pivotally mounted by one end in said bearing.
 8. Anindicator as defined in claim 7 wherein the means mounting the float forrotary movement comprises a bearing carried by the float mounteD on theother end of the rod.
 9. An indicator as defined in claim 8 furtherincluding means secured to the bearing secured in the casing forlimiting the arc swinging of the float.
 10. An indicator as defined inclaim 9 further including baffles secured to said rod and float fordamping the swinging and rotation of the float in a liquid.